I cleaned the track with my Atlas track cleaning car, I cleaned the wheels using the standard procedure ( 1 truck on a paper towel with alcohol and the 2nd truck on a DC powered piece of track ) , I swaped both trucks and still that MP15 stalls on turnouts at low speed . I even cleaned the flat brass springs that transmit the current from the trucks to the frame. Sometimes on straight tracks it stops but the light are still on and the wheels are spinning but the engine doesn't move ( I know that in this case it's not a contact problem because the wheels are spinning ). Any idea ? Wheels out of gauge ? It is locomotive dependent because my Life-Like SW9/1200 and my Atlas GP7 run perfectly. Tia for any suggestion.